1. Field of the Invention
The present invention relates to the field of portable personal computers and more particularly to an insulating board or heatshield used in connection with a portable personal computer to shield the user's lap from heat generated by the computer.
2. General Background and State of the Art
The proliferation of portable personal computers, or laptop computers, is well documented. Laptop computers are used by business travelers to perform virtually all of the tasks enabled by desk top computers during previously unproductive hours traveling on airplanes, in hotels, and generally away from the office. Laptops also offer an alternative to bulkier, space consuming desk top models, with the opportunity to readily take the laptop to remote locations such as lectures, business meetings, or the like, and also to bring one's computer home in the evenings to continue working on projects. The reduction in the size and weight of today's laptops render them indispensable to travelers and business people around the world.
Laptop computers, like desk top computers, include a processing unit or chip that performs calculations used in the operation of the laptop. The processing unit generates a substantial amount of heat, and as processors grow more powerful and faster (in the multi-Gigahertz range) the amount of heat that the chips generate continues to increase. In most desktop computers, there are fans, heat sinks and adequate airspace to dissipate the heat generated by the processor. However, in a laptop computer there is very little room for large fans or open airspace, so heat is transferred through the underside of the computer where it comes in contact with the user's lap. The processors can produce up to 100 watts per square centimeter—the equivalent heat generated by a light bulb, and temperatures can easily reach 115° F. or more. The push for smaller and lighter laptop computers exacerbates the problem of heat dissipation. The heat problem is a byproduct of consumer demand for smaller, faster computers with reasonable battery life because large fans and extra airspace require larger units with reduced battery life. As a result, the underside of a laptop computer is notorious for being very warm or even hot to the touch when it has been running for a period of time.
Left unchecked, the heat build up of the laptop computer is transferred to the user at the point of contact where the laptop rests on the user's lap. As the laptop heats up, the build up of heat may become uncomfortable and can even result in pain. In this event, the user must endure the discomfort or discontinue operation of the laptop to allow the unit to cool down. Once cooled down, the laptop will once again begin to heat up to the point where discomfort requires another shutdown to allow further cooling. This repeating pattern of working followed by forced breaks to allow the computer to cool down is unproductive and can be disruptive, not to mention the discomfort involved. As a result, others have attempted to solve this problem through various methods.
For example, a product marketed by Macally U.S.A. of Irwindale, Calif. called the “IcePad” comprises a two panel hinged device that allows air to circulate between the laptop and the user. However, the Icepad is heavy and bulky—two significant shortcomings when traveling. In addition, the Icepad has grooves or channels for airflow along its bottom surface that create an uneven surface, and such uneven surfaces can become uncomfortable to the user after prolonged use. Also, U.S. Pat. No. 6,474,614 to MacEachern discloses a heat dissipating laptop support comprising a trapezoidal stand with stackable risers to allow air to pass through while tilting the laptop toward the user (see FIGS. 6 and 7). The laptop sits on a column of spacers that can adjust in height depending upon the number of spacers used. However, one risk in this device is that the spacers may become uncoupled and dislodged, causing the laptop to fall, and the device is ill-suited for adjusting to variable sized laptops. In addition, U.S. Patent Publication No. US 2003/0080264 to Helmetsie et al. discloses a laptop support with Velcro® fasteners that include louvers to circulate air between the laptop and the support. These louvers define grooves on the underside of the support that bear against the user and may become uncomfortable over time. The iGo ErgoStand offered by iGo® products (www.igo.com) is a notebook stand that claims to “raise(s) your notebook for a more comfortable typing position and viewing angle,” and “increasing the airflow around your system allows it to run cooler.” The device is designed for resting on a table rather than a user's lap, and the large opening in the ‘X’ pattern will not shield the laptop heat from the users lap if the Ergo Stand should be placed between the laptop computer and the user's lap. Small rubber pads at the end of the four corners are designed to mate to the bottom plastic surface of the laptop. They are not large enough to mate with the friction pads on the bottom of laptops that are positioned on various locations based on the size and make of the laptop. Also, the shape and plain shell structure (the bottom of the Ergo Stand is hollow) does not offer a large bending moment of inertia and hence would not likely offer sufficient structural support. Other devices are known for supporting a laptop to provide a stable platform, but none of the prior art devices are well suited for the combination of heat dissipation and comfort.